Rinnai HDC11 Natural Gas Conversion Kit The Rinnai HDC11 Natural Gas Conversion Kit is the genuine article - we're talking a fully-approved solution from the manufacturers themselves to swap out a compatible Rinnai HDC series water heater from running onLPG (propane) to natural gas (NG). This kit has been engineered to meet Rinnai's lofty standards for safety, efficiency and reliability, so you can be sure your water heater is still performing like a champ even after the conversion, and you can even use it in places where natural gas isn't an option. Perfect for installing at home or for light commercial setups, this HDC11 conversion kit has all the bits and bobs you'll need for a seamless switch, plus it maintains the all important combustion characteristics and delivers consisten